IMP AEROSPACE Sea King Pylon Repair and Overhaul by Anick Chiasson Intermediate Aero/Mechanical Engineer Rotary Wing Engineering IMP AEROSPACE IMP Aerospace, P.O. Box 970, Enfield, Nova Scotia, Canada B2T 1L5 Tel. 902. 873.2250 • Fax 902 873 2290 • e-mail. impad@impgroup.com Website. www.impaerospaceanddefence.com

Presentation Outline Introduction Overview of the Pylon Areas of Interest on the Pylon Engineering Process Area 1: Tail Gearbox (TGB) Support Fitting Area 2: Pylon Fold Fitting Area 3: Oversized Rivets on left side of a Pylon Area 4: Hinge fittings Area 5: Oversized Fasteners at Hinge Fittings Questions

Introduction of IMP Group Ltd. Number of professionals IMP Group Ltd. IMP AEROSPACE & DEFENCE IMP AEROSPACE Engineering Branch Aeronautical Support Engineering Rotary Wing Engineering Fixed Wing Engineering Specialty Engineering = 22 = 26 = 12 = 32 Integrated Logistics Support (ILS) Technical Publications = 29 = 30

Overview of the Pylon Pylon The Pylon is the tail end of the aircraft.

Overview of the Pylon The Pylon holds the Tail Rotor and the Stablilizer. The Intermediate Gearbox (IGB) and the Tail Gearbox (TGB) are installed on the Pylon. The Pylon is under intense load (torsion and bending). The Pylon is a critical primary component of the Sea King.

Areas of Interest on the Pylon Area 1: TGB Support Fitting Area 4: Hinge Fittings Area 2: Pylon Fold Fitting Area 5: Oversized Fasteners at Hinge Fittings Area 3: Row of oversized Rivets along LH side

Engineering Process Sea King part or component is inducted in our facility. The damage is assessed. Production department requests Engineering services for a serviceability assessment. Engineering team calculates safe limits for rework/repair. Engineering team prepares a detailed repair scheme document.

Area 1 : TGB Support Fitting Mounting Pads and Bolt Holes Barrel Nut Holes Damage found inside barrel nut bore holes and bolt holes Damage found on Tail Gearbox (TGB) mounting pads

Area 2: Pylon Fold Fitting The power fold system was added to the Canadian version of the Sea King. Pylon Fold Fitting

Area 3: Oversized Rivets on left side of a Pylon FWD Rivet #1 UP Row of oversized Rivets (Quantity 55) was discovered at overhaul. The rivets found were 1/4” and the OEM design was 3/16”.

Area 4: Hinge Fittings Upper Hinge Fitting (Top View) Lugs Upper Hinge Fitting (Top View) The lugs are two of the attachment points to the aircraft fuselage. The four mounting pads are to install the Intermediate Gear Box. IGB Mounting Pads

Area 5: Oversized Fasteners at Hinge Fittings Upper Hinge Fitting Hi-Lok fasteners qty 11 on either side at upper hinge fitting UP FWD Hi-Lok fasteners qty 8 on either side at lower hinge fitting

Area 5: Oversized Fasteners at Hinge Fittings Initial Problems: 11 pylons with oversized fasteners at installation of Upper and Lower Hinge Fittings. No approved documentations were found to substantiate the oversized fasteners. Up to 0.292” from their original design size of 0.188”. Biggest problem was the lack of acceptable edge distance (ED) on the different structure parts.

Area 5: Oversized Fasteners at Hinge Fittings Assessment: Option 1 Option 2 Repairing the pylon by replacing the structure affected; and revert to 3/16” fasteners: 400 man-hours per pylon Lead time to get parts Material cost Manufacturing hours to manufacture parts needed Analyzing the damage for serviceability: The margins of safety of the Fittings were high The skin, cap angles and doubler had to be analyzed The analyses would render at least 8 pylons serviceable

Area 5: Oversized Fasteners at Hinge Fittings Example of the multiple layers within the Pylon. Plugging the oversized holes was required for this repair.

Area 5: Oversized Fasteners at Hinge Fittings Results: Engineering was able to analyze the structure with the oversized fasteners. Those completed and approved analyses rendered 6 pylons serviceable. More pylons will be deemed serviceable using the completed analyses. Fatigue limits in terms of life span for each pylon were achieved.

Area 5: Oversized Fasteners at Hinge Fittings Edge Distance (ED) less than 2D Splice cut line Example of spliced skin (above) Example of less than 2D edge distance (left)

Questions Thank you for the opportunity to highlight IMP’s Pylon R&O capabilities! Please come see a Pylon at our booth to discuss any further questions that you may have!